As described in, for example, JP-A-2003-530602 (FIGS. 16 and 17) and JP-A-2005-10498 (FIGS. 1 and 4 to 6), as a display for POP advertisement, self-supportable upright displays having a paperboard main body have been widely used. These displays are constructed in such a manner that when used, a main body folded into flat is unfolded into a tubular shape and allowed to stand, and when not used, the main body unfolded into a tubular shape is folded into flat and can be transported, stored, etc.
JP-A-2003-530602 (FIGS. 16 and 17) describes an information display structure comprising a main body made of two sheets having display faces formed thereon, wherein both ends of the sheets are connected so that the main body can be folded into flat and unfolded into a tubular shape; a center fabricating part and a fabrication end part which are protruded inwardly from both side ends of the sheets; and an elastic belt laid across therebetween. This information display structure has the above construction, and when one side of the main body folded into flat is grasped and lifted up, the main body is unfolded by the action of the elastic belt and forms a tube with each sheet projected into a circular shape, whereby the main body can stand on the floor, etc. And, when the two sheets are compressed in such a direction that the sheets overlap each other, the main body can be folded into flat. However, since this upright display is unfolded simply by pulling the two sheets by the elastic belt, there is a possibility that the two sheets cannot be securely unfolded.
Further, the display for exhibition described in JP-A-2005-10498 (FIGS. 1 and 4 to 6) comprises a main body made of two sheets of which both side end portions are connected; and a flat spring of a substantially V-shape in cross-section fixed to the inner face of each of the side end portions of the main body, wherein the main body folded into flat can be expanded and kept in a tubular shape by the unfolding force of this flat spring. However, when the main body (sheet) is formed to have a large width, it is impossible to enforce the unfolding force throughout the overall width simply by expanding the inner faces of both side end portions of the main body, and therefore the main body cannot be unfolded widely. In addition, as the above upright display, various types have been proposed, but fully satisfactory ones are few, because of complicated construction, or troubles at the time of folding and unfolding.